WASHINGTON — When President Obama announced a program to grant executive clemency to drug offenders given long mandatory sentences, Arnold Ray Jones did what more than 29,000 federal inmates have done: He asked Obama for a presidential commutation.

And then, after it arrived on Aug. 3, he refused to accept it.

Jones’ turnabout highlights the strings that come attached to an increasing number of Obama’s commutations: In this case, enrollment in a residential drug treatment program — which has been a condition of 92 of Obama commutation grants. Jones is the first to refuse that condition.

If Jones had agreed to complete the the program, he would be out in two years. He still has six years left on his original 2002 sentence for drug trafficking, but Jones may be counting on getting time off for good behavior, which would have him released in April 2019 — eight months longer than if he had accepted the commutation. ​Jones is in a low-security federal prison in Beaumont, Texas.

The unusual rejection came to light last week, when Obama commuted the sentences of 102 more federal inmates. With the 673 previous commutations granted, the total should have been 775 — but the White House accounting had only 774.

At about the same time, the Department of Justice updated its online record of Obama's commutations and updated Jones' entry with the notation: "condition declined, commutation not effectuated."

The White House and the Justice Department declined to talk about the specifics of the case. But inmate records that Jones submitted as part of his court case show that he used crack cocaine weekly in the year before his arrest, and that drug treatment programs he's completed in the past have been unsuccessful.

The Bureau of Prisons describes its Residential Drug Abuse Program as its most intensive treatment program, where offenders are separated from the general population for nine months while participating in four hours of community-based therapy programs each day.

Jones' mother said Thursday that she was excited about the news of Obama's commutation and wasn't aware that it was rejected. "I don’t know about him declining or anything. I'm looking for my son to come home," said Ruth Jones, of Lubbock, Texas.

Unlike pardons, which represent a full legal forgiveness for a crime, commutations can shorten a prison sentence while leaving other consequences intact. And as Obama has increased his use of commutations in his last year in office, he's also gotten more creative in adapting the power to fit the circumstances of each case. Unlike the more common "time served" commutations, which release a prisoner more or less immediately, many of his commutations since August have been "term" commutations, which have left prisoners with years left to serve on their sentences.

At the same time, Obama has also begun to attach drug treatment as a condition of many of those pardons, beginning with Jones' class of 214 commutations on Aug. 3 — the single largest grant of clemency in a single day in the history of the presidency.

That day, White House Counsel Neil Eggleston — who advises the president on commutation applications, explained the new drug treatment condition in a blog post on the White House web site.

"For some, the president believes that the applicant’s successful re-entry will be aided with additional drug treatment, and the president has conditioned those commutations on an applicant’s seeking that treatment," Eggleston wrote. "Underlying all the President’s commutation decisions is the belief that these deserving individuals should be given the tools to succeed in their second chance."

Since Aug. 3, 22% of the commutations he's issued have required drug treatment.

Conditional pardons and commutations have been part of presidential clemency almost since the beginning. Presidents have used that power to induce prisoners to join the military, leave the United States or even — in the case of President Warren Harding's pardon of socialist Eugene Debs — that the clemency recipient travel to Washington to meet him.

President Bill Clinton imposed conditions in 34 cases, usually insisting on drug testing.

It's not the first time Obama has attached conditions, either. In January, he granted clemency to seven Iranians accused or convicted of of espionage as part of a "humanitarian gesture" that has since been criticized by congressional Republicans as a hostage swap. All seven had to agree not to sue the federal government over their detention, and Obama included a "Son of Sam" clause prohibiting them from profiting off the publicity from their crimes.

But it's extremely rare for a recipient to reject clemency outright once it's granted. P.S. Ruckman Jr., a political scientist who has cataloged 30,642 presidential clemency actions dating back to President George Washington, has found just 16 clemency warrants returned to the president unaccepted.

Take President Herbert Hoover's 1930 commutation of Romeo Forlini, an Italian man serving a seven-year sentence after being caught by the Secret Service selling fraudulent Italian bonds. That commutation was granted "on condition that he be deported and never return to the United States."

Forlini rejected that condition, and two weeks later Hoover granted him a full, unconditional pardon. "There's a guy who played his cards right," Ruckman said. (Alas, Forlini was arrested in New York in 1931 trying to pull off a similar scam on an undercover detective.)

In 1999, Clinton offered to commute the sentence of 14 members of a Puerto Rican nationalist group tied to terrorism. Twelve accepted, but two of them rejected conditions that required them to renounce violence.

Others have accepted presidential clemency only to challenge the conditions after the fact. In 1960, President Dwight Eisenhower commuted the death sentence of a man convicted in a military court for murder, on the condition that he not be eligible for parole. The Supreme Court upheld that condition in 1974.

And Teamsters Union boss Jimmy Hoffa accepted a pardon from President Richard Nixon on the condition that he never again participate in managing a labor union. Hoffa was planning to challenge that condition when he disappeared in 1975.